Fortified Riebeckite
Fortified Riebeckite (#5685F9) is a true azure with a cool character. It leans cool, sitting on the blue, green, and violet side of the wheel. Quiet and dependable, a fit for product UI and data visualization. Its HSL profile (223°, 93%, 66%) places it in the highly saturated band at a mid lightness. Best used in small doses, like logos, CTAs, focus rings, or highlight text, where its saturation becomes a feature rather than noise. For a confident two-color system, pair it with its complementary amber. For something softer, pull in its analogous neighbors on either side of the wheel.
Etymology
Latin fortificāre, to make strong — past-participle of fortify. As a color modifier, fortified implies a saturated-and-strengthened-and-defensive quality, the deep-rich color of Vauban-style military-fortification stone-and-earth rampart-and-bastion architecture. Sits at the bold-and-fortified end of the grid, parallel to bastioned and armored.
A sodium-iron amphibole — the source of crocidolite (blue asbestos) and the chatoyant inclusions in hawk's-eye quartz. Mined principally in South Africa and Australia. The color refers to a freshly cleaved riebeckite specimen: a deep, slightly cool dark blue-gray with the slight metallic shine of amphibole.
Closest matches
The nearest named color in three reference sources, ranked by perceptual distance (ΔE76 in CIELAB). ΔE < 1 is imperceptible to most viewers; ΔE > 10 is clearly different. When two sources point to the same hex they’re merged into one tile; click any to open that color’s page.
Variations
Click any swatch to exploreHarmonies
Accessibility
How this color appears to viewers with the four major color-vision-deficiency types. Computed via the Machado (2009) physiologically-based model. If a tile matches the original, the color reads the same to that viewer.
The color used as foreground text against pure white and pure black, with the contrast ratio and WCAG 2.1 grade. Aim for AA (4.5:1) for body text and AA Large (3:1) for 18 pt+ headlines; AAA (7:1) is the gold standard for long-form reading surfaces.